The coaching carousel continues to spin in the NBA. In recent days, the Los Angeles Clippers – coming off the best season in franchise history – have decided not to bring back Vinny Del Negro as head coach. The Phoenix Suns -- coming off their worst season since they were in expansion team in the late 1960s – have decided to turn to Jeff Hornacek to lead their team back to respectability. And the Atlanta Hawks – who were essentially average this last season – have turned to Mike Budenholzer to lead the team next year.
These are hardly the only teams to make a change. Since the end of the 2012-13 NBA season, the Brooklyn Nets, Charlotte Bobcats, Cleveland Cavaliers, Detroit Pistons, Milwaukee Bucks, and Philadelphia 76ers have all decided that the person who coached the team at the end of this past season shouldn’t be around for the next season. In all, at least nine of the 30 NBA teams will have a new coach next year.
These changes – as I have argued before --will probably not make much difference. A study published in the International Journal of Sport Finance (full PDF here) – which I conducted with Mike Leeds, Eva Marikova Leeds, and Mike Mondello – found that most NBA coaches across a sample covering 30 years did not have a statistically significant impact on player productivity. And in other sports, we also have evidence that coaches cannot systematically change outcomes.